Squash Lady Beetle Larva: Quick and Essential Guide

Squash Lady Beetles, also known as Squash Beetles, are a type of ladybug and a common vegetable pest, particularly in the eastern United States. They have a strong preference for plants of the gourd or squash family, which includes melons, pumpkins, squash, and cucumbers. As a gardener or a plant enthusiast, understanding the larva stage of the Squash Lady Beetle is essential for effective management and prevention of damage to your plants.

The larva of the Squash Lady Beetle is quite different from the adult beetle, both in appearance and behavior. It’s important to recognize these differences so you can identify them in your garden as early as possible. In this article, we’ll discuss the life cycle, characteristics, feeding habits, and ways to manage Squash Lady Beetle larvae in your garden. By being well-informed, you’ll be able to better protect your beloved cucurbits from these damaging pests.

Identification of Squash Lady Beetle and Its Larva

Physical Features of Adult Lady Beetle

The adult Squash Lady Beetle, also known as Epilachna borealis, is typically characterized by its yellow or orange color and dome-shaped body 1. To help further identify this particular beetle, here are a few notable features:

  • Copper-colored body
  • Seven large black spots on each wing covering (elytra)
  • Four black spots on the thorax (middle body section)

When you encounter these beetles, you might notice their strong preference for cucurbits, which includes plants such as melons, pumpkins, squash, and cucumbers2.

Physical Features of Larva

The larva of the Squash Lady Beetle differs in appearance when compared to the adult beetle. Here are some key characteristics of the larva:

  • Light yellow body
  • Rows of stout branched spines on the body
  • About 1.6 mm in length when newly-hatched3

As you identify these larvae on your plants, it’s important to remember that their primary food source is the leaves of cucurbits, and they often cluster together on the undersides of these leaves4. By keeping these facts in mind and understanding the physical features of both adult and larval Squash Lady Beetles, you will be better equipped to deal with these pests in your garden.

Life Cycle of Squash Lady Beetle

Egg Stage

The life cycle of the Squash Lady Beetle begins with the Egg Stage. Adult beetles lay their eggs in clusters or egg masses on the underside of host plant leaves, typically on cucurbit plants such as squash, cucumber, and pumpkin1. When you observe these clusters, you might notice that the eggs are small, oval, and yellowish-orange in color.

Larvae Stage

In the Larvae Stage, the beetle larvae emerge from the eggs and start to feed on the plant tissue between leaf veins2. The larvae are spiny, yellow or orange in color, with dark brown heads. They can cause significant damage to the host plants by creating “windowpaning” or scraping injuries on the leaves.

  • Spiny larvae
  • Yellow or orange in color
  • Dark brown heads

Pupa Stage

Eventually, the larvae will enter the Pupa Stage and pupate, often on the undersides of leaves or hidden in plant debris3. During this stage, they transform from larvae into adult beetles while being enclosed in a protective case. It’s important to monitor host plants during this stage, as the next generation of adult beetles will soon emerge, ready to lay eggs and continue the cycle.

Adult Stage

In the Adult Stage, the Squash Lady Beetles develop their distinctive copper color, round dome-shaped bodies, and 14 spots on their wing coverings4. Although they resemble the Mexican bean beetle in size and shape, adult Squash Lady Beetles have a slightly different color and fewer spots. These beetles feed on cucurbits, continuing the cycle by laying new egg masses for the next generation.

In summary, the life cycle of the Squash Lady Beetle consists of the following stages:

  1. Egg Stage: clusters of yellowish-orange eggs on leaf undersides
  2. Larvae Stage: spiny, yellow or orange larvae feeding on leaf tissue
  3. Pupa Stage: transformation from larvae to adult in protective case
  4. Adult Stage: copper-colored beetles with 14 spots, feeding on cucurbits and laying eggs

Feeding Habits

Squash Beetle Larva Diet

Squash Lady Beetle Larva, also known as Epilachna borealis, are known for their preference for plants from the gourd or squash family, specifically cucurbits like squash, melons, pumpkins, and cucumbers1. Their feeding habits consist of consuming the tender leaf tissue of these plants, leaving the tougher leaf veins untouched. This type of feeding leaves the leaves with a tattered, skeleton-like appearance.

For example, when the larvae feed on cucumber leaves, they create small holes, giving the leaves a lace-like appearance.

Squash Lady Beetle Adult Diet

As adults, Squash Lady Beetles continue to feed on the same plants as they did in their larval stage. However, their diet may expand to include other crop plants like beans and legumes2. Like the larvae, adult beetles consume the leaf tissue of their preferred plants, but they also feed on the flowers and fruits, causing additional damage.

Here is a comparison of the diets of Squash Lady Beetle Larva and Adults:

Stage Preferred Plants Feeding Parts
Larvae Squash, Cucumbers Leaf Tissue
Adults Squash, Cucumbers, Legumes, Beans Leaf Tissue, Flowers, Fruits

Remember, the Squash Lady Beetle can cause significant damage to your plants, and it’s essential to monitor their population and take preventive measures if you notice an infestation.

Habitat and Geographical Range

The Squash Lady Beetle Larvae, also known as Epilachna borealis, can be commonly found in gardens and fields where squash plants like zucchini grow. You can encounter them mainly in the eastern United States where they have a strong preference for cucurbits such as melons, pumpkins, squash, and cucumbers.

These larvae thrive in warm climates. It’s not uncommon to find them extending their range southward, reaching places like Mexico. This means that you’ll need to be vigilant when tending to your garden, particularly if you live within their geographical range.

Remember,habitat plays a vital role in the activities of these larvae, so it’s important to consider geographical area and the type of plants in your garden when planning a response to their presence.

Pest Management and Control Strategies

Chemical Control

There are some insecticides that can help you with controlling squash lady beetle larvae. For instance, products containing neem oil come in handy. Neem oil is derived from the neem tree and effectively kills squash lady beetle larvae when they consume it. Here are some pros and cons of using neem oil:

  • Pros:
    • Organic and safe for the environment
    • Can control other garden pests too
  • Cons:
    • May need multiple applications
    • Less effective on mature beetles

Another option is using insecticidal soap. This soapy water solution is sprayed onto the affected plants, especially the underside of leaves where larvae can be hiding.

Non-Chemical Control

If you prefer non-chemical methods, try the following options:

  1. Handpick: One of the easiest methods is to simply handpick the squash lady beetle larvae from your plants. This can be time-consuming but is an effective way to remove the pests.
  2. Trench: Dig a narrow trench around the perimeter of your garden or plant bed. This can help prevent the beetles from reaching your plants. Just ensure you maintain it regularly by removing any larvae or beetles that fall into the trench.
  3. Row Cover: Using a floating row cover can protect your plants from squash lady beetle larvae. Just make sure you install and remove the cover properly to prevent any damage to your plants.
  4. Organic Control: You can introduce beneficial insects, such as ladybugs, to your garden. These predators will help control the squash lady beetle larvae population.

Remember, choosing the right strategy depends on your specific situation and preferences. Keep it brief and choose the method that suits your needs. With proper care and attention, you can successfully manage squash lady beetle larvae in your garden.

Common Plants Affected

Effect on Squash

Squash Lady Beetle Larva, also known as Epilachna borealis, primarily targets plants in the squash family, or Cucurbitaceae1. This includes various types of squash, such as summer and winter squash, as well as pumpkins and gourds. They tend to feed on the tissue between leaf veins5, causing significant damage to squash plants.

The larvae can cause severe damage to the leaves, and in some cases, completely skeletonize them. This weakens the plant and hampers its ability to produce fruit.

Effect on Beans

Although Squash Lady Beetle Larva has a strong preference for cucurbits1, it can occasionally be found on bean plants. However, it’s important to note that this is less common. Beans are not the primary host plant for these larvae, and their damage to bean plants is typically minimal compared to the destruction they can cause in squash plants.

Effect on Cucumbers

Cucumbers, being part of the Cucurbitaceae family1, are also susceptible to the Squash Lady Beetle Larva. Similar to squash plants, they can experience significant leaf damage, leading to reduced fruit production.

To summarize, Squash Lady Beetle Larva primarily targets cucurbits, with squash and cucumbers being the most heavily affected plants. While beans may occasionally be affected, the impact on them is minimal compared to that on squash plants.

Preventing Squash Lady Beetle Infestations

To prevent squash lady beetle infestations in your garden, there are several methods you can use. One effective way is to use soapy water. You can simply mix a few drops of dish soap with water in a spray bottle and apply it to your plants. This can help deter the beetles and keep your plants safe.

Another important step in preventing infestations is to keep your garden clean by regularly removing plant debris. This will help eliminate the beetles’ hiding places and prevent them from laying eggs on your plants.

You can also use a row cover to protect your plants. This shield can keep the beetles away from your plants and make it harder for them to access your squash. However, remember to remove the cover during the harvest season, as it may restrict pollinators.

Keep an eye out for any signs of beetle damage, such as skeletonize leaves or scraping marks. If you notice these signs, take action immediately to prevent further damage to your plants.

Here is a quick comparison of the methods mentioned above:

Method Pros Cons
Soapy water Easy to apply; inexpensive May need repeated applications
Plant debris Removes hiding places for beetles Requires regular maintenance
Row cover Provides physical barrier May restrict pollinators during harvest

Remember, it’s important to stay vigilant and maintain a clean garden to keep the squash lady beetle population under control. With a combination of these methods, you can help protect your plants and keep infestations at bay.

Difference Between Squash Lady Beetles and Other Similar Species

In this section, we will explore the differences between Squash Lady Beetles and three other similar species: Cucumber Beetle, Mexican Bean Beetle, and Beneficial Lady Beetle.

Squash Lady Beetle vs Cucumber Beetle

Squash Lady Beetles (Epilachna borealis) are a type of ladybug that can become a common vegetable pest in the eastern US, with a strong preference for cucurbits, such as melons, pumpkins, squash, and cucumbers1. On the other hand, Cucumber Beetles are known pests that damage cucumber plants as well as other crops6.

  • Squash Lady Beetles have a distinctive orange to tan color with seven large black spots on each wing2.
  • Cucumber Beetles, generally greenish-yellow in color with black spots or stripes, are smaller than Squash Lady Beetles7.

You can distinguish the two species by considering their colors, sizes, and patterns.

Squash Lady Beetle vs Mexican Bean Beetle

Mexican Bean Beetles (Epilachna varivestis) are close relatives of Squash Lady Beetles and pose as serious pests on bean plants3.

  • Similar to Squash Lady Beetles, Mexican Bean Beetles have orange to tan coloration with spots on the wings4.
  • The key difference is the larger spots on the wings of Mexican Bean Beetles.

To differentiate these species, examine the size of the spots on their wings.

Squash Lady Beetle vs Beneficial Lady Beetle

While Squash Lady Beetles can damage your garden, Beneficial Lady Beetles are allies that help control aphids and scale insects5.

  • Squash Lady Beetles and Beneficial Lady Beetles might show similar orange or red colors, but the spot pattern on their wings differs.
  • Beneficial Lady Beetles have a more rounded shape and often exhibit different coloring, patterns, or number of spots8.

To differentiate the two, observe their shape, coloring, and spot patterns. Encouraging Beneficial Lady Beetles into your garden is advantageous, as they help keep pests under control5.

Interaction with Other Pests

When it comes to squash beetles and lady beetles, there are some key differences to understand. For example:

Squash Beetles:

  • Prefer cucurbit plants like squash and pumpkins
  • Known as pests in the garden
  • Lay eggs on the underside of leaves
  • Can skeletonize leaves by feeding on them

Lady Beetles:

  • Feed on garden pests such as aphids
  • Known as beneficial insects in the garden
  • Lay eggs near aphid colonies
  • Can help control pest populations

In your garden, you may also encounter Mexican bean beetles, which are similar to squash beetles. These beetles prefer feeding on bean plants and can cause damage to various crops. Maintaining a healthy garden can involve monitoring and controlling all three of these beetle types.

When it comes to managing these pests, it’s important to recognize their distinctive characteristics, such as the shiny, slightly oval, copper-colored eggs of squash bugs and the round, yellow eggs of lady beetles. It’s also crucial to know their preferred host plants and their feeding habits.

A proactive approach to managing your garden pests can involve:

  • Regular inspections of your plants to spot signs of damage
  • Removing any infested plant material
  • Using organic or chemical pesticides when necessary
  • Encouraging natural predators like lady beetles and lacewing larvae that feed on aphids

By understanding the interaction between squash beetles, lady beetles, and Mexican bean beetles, you can better protect your plants and maintain a thriving garden.

Interesting Facts About Squash Lady Beetle

Squash Lady Beetle, scientifically known as Epilachna borealis, belongs to the Coccinellidae family, which is commonly known as ladybird beetles. These beetles are generally considered beneficial insects as many of them feed on aphids and other pests. However, Squash Lady Beetles have a different feeding pattern and can be problematic for gardeners.

  • They are particularly fond of plants in the cucurbit family, including cucumbers, melons, pumpkins, and squash.
  • Squash lady beetles are known for laying their copper-colored, slightly oval-shaped eggs on leaves, mainly on the underside, where they are protected from predators and environmental factors.
  • Adult beetles are yellow or orange, with seven large black spots on each wing covering and four black spots on their thorax.

In terms of their behavior and activity, squash lady beetles generally become more active in July when they start to feed on plants and lay their eggs. They are capable of flying, which allows them to easily locate food sources and mates.

Some notable characteristics of squash lady beetles include:

  • Squash lady beetles can cause significant damage to plants by feeding on the tissue between leaf veins, which ultimately weakens the plants and makes them susceptible to diseases.
  • Both adult beetles and larva feed on plants, causing damage in local gardens where they are found.

Despite being a pest in the garden, squash lady beetles play a role in the natural ecosystem. They serve as food for other insects and animals, like birds and spiders, that aid in pest control. By knowing more about these beetles and their habits, you can better manage their presence in your garden and reduce the damage they cause to your plants.

Role of Squash Lady Beetles in the Ecosystem

Squash Lady Beetles, scientifically known as Epilachna borealis, play a unique role in the ecosystem. They are a common garden pest, especially in the eastern US, where they target crops in the cucurbit family, including melons, pumpkins, squash, and cucumbers source.

While it’s important to discuss their harmful activities on garden plants, it’s also essential to mention that Squash Lady Beetles are part of the lady beetle family. Most lady beetles are incredibly beneficial to your garden as they consume many other pests. However, the Squash Lady Beetle stands out as a less beneficial member because of its feeding habits on cucurbit crops.

During their larval stage, these pests can cause significant damage to plants. They are yellow and covered in spines, which is a distinct feature that helps gardeners identify them source. The damage they inflict on plants includes scraping or “windowpaning” the tissue between leaf veins, leading to weakened and vulnerable crops source.

Here’s a quick comparison between squash lady beetles and other lady beetles:

Characteristics Squash Lady Beetles Beneficial Lady Beetles
Size Larger than most lady beetles (about ½ inch long) Smaller (about ¼ inch long)
Color Copper colored with 14 spots Red or orange with various numbers of spots
Larvae Yellow and covered in spines Similar but often found feasting on aphids or other small pests
Diet Cucurbit crops (e.g., squash, cucumber) Predatory, consuming aphids and other small garden pests
Impact Negative, causing damage to garden plants Positive, helping maintain healthy and pest-free gardens

So, while it might be tempting to generalize all lady beetles as helpful garden warriors, keep an eye out for Squash Lady Beetles and their larva as they can cause more harm than good to your cucurbit crops.

Consequences of Squash Lady Beetle Infestations

Squash Lady Beetle larvae can cause significant damage to your plants during the growing season. These pests are particularly fond of cucurbits, including melons, pumpkins, squash, and cucumbers.

An infestation could be detrimental to your crops as these larvae feed on the leaf tissue, making it difficult for the plants to photosynthesize. As a result, your plants’ growth may be stunted, and their overall health could decline.

Some of the consequences of Squash Lady Beetle infestations include:

  • Holes in leaves: The larvae feed on the tissue between leaf veins, which can create a “windowpaning” effect or even result in holes in the leaves, making the plant more susceptible to disease.
  • Damaged rind or skin: During the growing season, these larvae can also feed on the rind or skin of the fruits, compromising their quality and making them more vulnerable to rot.
  • Lost flowers: Squash Lady Beetle larvae might feast on your plants’ flowers, which can lead to a reduction in fruit production. If too many flowers are damaged, your overall yield may be noticeably lower.

In conclusion, a Squash Lady Beetle infestation should not be taken lightly. They can have devastating effects on your plants’ health, yield, and overall appearance. It’s crucial to monitor your garden closely and take appropriate action to prevent or manage any infestations.

Companion Planting to Discourage Squash Lady Beetles

When planning your garden, consider companion planting to help reduce the presence of squash lady beetles, a common pest of cucurbits. Let’s explore some plants that can help achieve this goal.

Nasturtiums are a popular choice for repelling squash lady beetles. They have a strong scent that deters pests from nearby squash plants. Plant nasturtiums close to your squash to take advantage of their protective properties. As an added bonus, nasturtium flowers are edible and can brighten up your garden and salads.

Petunias can also help protect your squash plants. These colorful flowers can help keep away squash lady beetles and other pests. Plant them near your squash to create a barrier and improve the overall appearance of your garden. Petunias come in many colors, so you can select varieties that complement your garden design.

Here’s a simple comparison table to help you decide which companion plant to use:

Companion Plant Beetle Deterrent Aesthetics Edible
Nasturtiums Yes Colorful Yes (flowers)
Petunias Yes Colorful No

In addition to these specific plants, consider a diverse mix of flowers, herbs, and vegetables in your garden to support beneficial insects and create a more balanced ecosystem.

Remember, no companion planting strategy is foolproof, but by incorporating plants like nasturtiums and petunias in your garden, you can reduce the likelihood of squash lady beetles becoming an issue. Happy gardening!

The Effect of Squash Lady Beetle Larva on Different Squash Varieties

Squash Lady Beetle Larva, or Epilachna borealis, is a common pest that affects a variety of plants, especially those in the cucurbit family. In this section, we’ll look at the impact of this pest on different varieties of squash.

Effect on Pumpkin

Squash lady beetle larva can cause visible damage to pumpkin plants. They feed on the leaves, creating a “windowpaning” effect, where they scrape the tissue between the leaf veins, causing the leaves to become weak and vulnerable. This can lead to reduced plant growth and yield. Ensure you keep an eye on your pumpkin plants for any signs of larval activity.

Effect on Zucchini

Zucchini plants are vulnerable to squash lady beetle larva, where they feed on foliage. As a result, the plants suffer from weakened leaves and reduced productivity. To keep your zucchini healthy, monitor your plants for any larval presence and take necessary control measures if required.

Effect on Gourds

Although gourds can be affected by squash vine borer larvae, they are not heavily targeted by squash lady beetle larva. While you still need to be vigilant about the presence of these pests on your gourds, their effect is less severe compared to other squash varieties.

Effect on Watermelon

Fortunately, watermelon plants are not typically targeted by squash lady beetle larva. Their impact on watermelon plants is minimal, so you may not need to be as concerned about these pests when growing watermelons.

Effect on Melons

Melons, such as cantaloupe, can also be subjected to some degree of damage by squash lady beetle larva. However, compared to other cucurbit plants like pumpkin and zucchini, the damage is relatively limited. Melon growers should still keep an eye out for any signs of larval activity, though.

Effect on Cucumbers

Cucumber plants can fall victim to squash lady beetle larva, which affects their foliage and can lead to weakened plant growth. It’s essential to be vigilant when growing cucumbers and consider implementing control measures as needed to protect your plants.

In summary, each variety of squash can experience varying levels of damage from squash lady beetle larva. It’s essential to understand the specific impact on your plants and take appropriate control measures to ensure a healthy and productive garden.


  1. Troublesome lady beetles: Mexican bean and squash beetles 2 3 4 5 6 7
  2. Squash Beetle – Home and Garden IPM from Cooperative Extension 2 3 4
  3. Mexican bean beetle – Epilachna varivestis Mulsant 2 3
  4. Lady Beetles in the Landscape | NC State Extension Publications 2 3
  5. https://extension.umd.edu/resource/squash-beetle-vegetables 2 3
  6. https://www.almanac.com/pest/cucumber-beetles
  7. https://hgic.clemson.edu/factsheet/cucumber-beetle-management-in-the-home-garden/
  8. https://www.goodhousekeeping.com/home/gardening/a20705603/what-do-ladybugs-eat/


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

18 thoughts on “Squash Lady Beetle Larva: Quick and Essential Guide”

    • I started seeing these pests eating my summer squash, zucchini, pumpkins,and winter squash three years ago and never had seen them before. Finally I had to spray them with Malathion and it works very well. Make sure to check the ” days to harvest” on the label. And of course wash the beans well before cooking. I pick the beans then immediatley spray the plants with the insecticide. This will allow the plants time to grow more beans until you do the same cycle again.

    • I am not an organic grower, as I have tried several “natural” concoctions over the years, (I have been growing a large garden for 45 years and have found most of the natural controls to be inneffctive). Malathion works very well. Most pesticides are fine when used as directed. These yellow creatures when leaves get in short supply in the fall will at the squash themselves.

  1. Are those lady battle larva bugs poiseness because my son just poked his finger on one…please let me know thanks

    • Lady Beetle Larvae have no poise, nor are they poisonous. This particular Lady Beetle is unique in that it is a plant feeder, while most others are predatory. Other Lady Beetles, both adults and larvae, help gardeners battle insect pests like Aphids.

  2. Rhoni, I think the insect you have eating your bean plants are Mexican Bean Beatles. The adults are bronze in color with black spots. Their larva are little fuzzy yellow creature which skeletonize the leaves of the bean plant and sometimes eat holes in the beans themselves. Malathion works well on them, but make sure you check the label for “days to harvest” after applying .

    • I hand picked off a bunch of larvae today and dropped them in soapy water. Kind of gross, but I find it’s often the best way to get pests out of the garden without resorting to pesticides.

  3. That is NOT a squash beetle. I went to the bug guide a few weeks ago and it has this wrong. It’s a Mexican bean beetle. They’ll go after not just beans, but squash, tomatoes, and several other variety of plants. They killed my squash this year, partly because I didn’t realize the adults were not just an orange-yellow variety of ladybug. I just found one on my cherry tomato plant, so I have to figure something out.

    • Don’t be too certain. Both the Squash Lady Beetle and the Mexican Bean Beetle are in the same genus and have similar looking larvae. Here is a BugGuide image of the Mexican Bean Beetle and here is a BugGuide image of the Squash Lady Beetle larva. According to BugGuide, the Mexican Bean Beetle feeds upon “Beans, soybeans, cowpeas, clover, alfalfa, kudzu, and beggartick/beggarweed.” According to BugGuide, the Squash Lady Beetle feeds on “leaves of squash, cantaloupe, and other cucurbits; an unusual characteristic is that this insect circles the leaf area in which it is going to feed.” In retrospect, we would consider any member of the subfamily Epilachninae, and you can see the entire life cycle depicted on BugGuide.

  4. I just found these bugs on the underside of my zucchini plants. This is the first time I’ve seen them, and yes, I do think they were preceded by an orange ladybug type insect that I thought was a ladybug. They ate quite a bit of the leaves before I found them. On some other zucchini plants there were these spider-like insects. A nightmare. I just tried coating the underside of the leaves with sulfur powder and will let you know if that works. If that doesn’t work I’ll try diatomaceous earth. I don’t like using poison.

  5. I have those yellow bugs with black spikes eating the leaves of beans, cucumbers, and zucchini. Are they different on each plant?


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